Starter control



Feb. 19, 1935. H. C, HOWSAM 1,991,939

STARTER CONTROL Filed NOV. 8, 1935 ffy/ffy@ fa C 26a/Jaw.

a, MAKERS Mii) BREAKtRS.

Patented Feb. 19, 1935 STARTER CONTROL lilyard C. Howsam, Chicago, Ill., assignor to Hubbard Spool Company, Chicago, Ill., a corporation of Illinois Application November 8, 1933, Serial No. 697,148

3 Claims.

My invention relates to starter control adapted particularly for use in connection with hydrocarbon engines for controlling the circuit of the electric motor for starting the engine.

An important object of the invention is to provide a switch structure for the starting motor circuit having a movable switch member adapted to be moved manually or by foot power for electrical engagement with switch terminals, and with the provision of means automatically controlled by the engine for preventing such electrical engagement when the engine is self-operating.

A further object is to provide, in a switch of the type referred to, insulating means movable by means automatically controlled by the engine into position between the movable switch member and the switch contacts or terminals when the engine becomes self-operating.

A further object is to provide, in a switch of the type and for the purpose referred to, an insulating medium which, when the engine is below minimum speed, will not interfere with complete mechanical and electrical operation of the switch but which, when the engine becomes or is selfoperating, will be automatically located to prevent electrical functioning of the switch and the closure of the motor circuit so that the motor cannot be connected with the engine while it is self-operating.

The above referred to and other features of the invention are incorporated in the structure disclosed by the drawing, in which drawing:

Figure 1 is an elevation of a hydro-carbon engine with accessories including a starting motor, and showing my improved switch and controlling structure applied in position to be actuated by overthrow movement of a clutch pedal;

Figure 2 is an elevation view of the switch structure with the switch terminal supporting cover structure removed;

Figure 3 is an inside elevation of the cover structure; and

Figure 4 is an enlarged longitudinal section on plane IV--IV Figure 2.

The switch structure shown comprises a rectangular case or housing 1G preferably of sheet metal which is open at the bottom and whose longitudinal walls at their lower ends have lateral reflection forming seating anges 11, shown as of triangular shape. These flanges form seats for a cover structure or plate 12 whose sides are shaped to iit the flanges 11 to seat thereon, the end walls of the case having tongues 13 extending therefrom which are deflected over against the cover plate to lock it in place,

The cover structure supports the contact posts or screws 14, 14 extending in the cover plate with their and 16' within the case 1 are engaged by securing through openings 15 flat contact heads 16 0. The terminal screws nuts 17 between which and the cover plate washers 18 of insulating material are interposed and between the contact heads of the screws and the cover plate insulating material 19 is interposed, said insulating material being shown in of rectangular shape ing 10. The terminals are sulated from the case the form of a plate or sheet 10 to fit the mouth of the casthus electrically inand its cover plate. A wall or loop 20 of insulating material may also be suitably supported from the cover plate to extend between the terminals to prevent arcing or accidental short-circuiting of the terminals.

The top of the case 10, at a point mid-way between the terminals 14 and 14', has a guide open- 20 ing 21 f end carries a switch or a stem or plunger 22 which at its lower blade structure. As shown,

the switch blade structure comprises an inverted U-shaped switch blade 23 deected at its end to form U-shaped contact feet 24 and 24 which 25 are dispose tact heads 16 and 16 reduced end 25 of the plung between the shoulder or welded to the reduce terial 27 being interpose d vertically above the terminal con- The blade 23 receives the er 22 to be secured and a washer 27 riveted d end 25, insulating mad between the blade and the plunger structure. Preferably, also a spring plate 28 is secure d with the blade to extend across the top thereof with its ends engaging in the contact feet 24 and 24 so that the switch blade structure is more or less resilient.

The case 10 has a lining 29 of insulating m rial, the lining shown being ateof U-shaped crosssection with its bottom engaging against the inner side of the top of the case and its side walls 29' engaging against the case and terminating a tact heads 16 and 16 of wall of the insulating lining for the plunger structure 22.

the plunger structure to the top of the casi telescopically receive sheet metal whose bo end of the plunger 22, between the head and the guide passageway 21 during vertical reciprocation thereof.

longitudinal walls of the distance above the conthe terminals. The top has a passageway 30 Concentric with is a tubular shell 31 secured ng l0. This shell at its top the cup shaped head 32 of ttom is riveted to the upper the telescopic engagement wall 31 assisting the in guiding the plunger 22 A coil spring 33 within the wall 31 and the head 32 abuts the head and the top hold the plunger in of the case 10 and tends to 55 its upper position with the plunger electrically insulated from the case 10.

In Figure 1 I have shown the switch structure associated with the hydro-carbon engine E for controlling the circuit for the engine starting motor M. I have shown the switch structure secured so that the actuating head 32 thereof is in the path of the clutch pedal P to be depressed during overthrow swing of the pedal after release thereby of the clutch (not shown) for connecting the engine with the driving gearing. A suitable bracket structure 34 extending from the engine or vehicle framework is provided for supporting the switch structure, suitable bolts or rivets 35 extending through the bracket and registering holes 36 and 37 in the casing flanges 11 and in the cover plate 12, these bolts or rivets serving also to more securely hold the cover plate to the casing. It is evident that, instead of mounting the switch for actuation by the clutch pedal, it may be mounted so as to be depressed manually or directly by the foot of the driver.

The terminal 14 of the switch is connected by conductor 38 with one terminal of the motor whose other terminal is grounded to the vehicle framework, and the other switch terminal 14' is shown connected with a conductor 39 which leads to one terminal of the vehicle battery (not shown) whose other terminal is grounded. When the switch head 32 is depressed the switch blade will be carried into engagement with the terminals 14, 14 to close the starting motor circuit for starting of the engine.

It is very important to prevent closure of the starting motor circuit and connection of the motor with the engine while the engine is self-operating or running at a comparatively high speed. Means are therefore provided automatically controlled by the engine for preventing electrical engagement of the switch blade with the switch terminals when the engine is self-operating. I make use of the vacuum or suction in the engine manifold for operating such automatic means. As shown a diaphragm housing 40 is secured to one end of the switch casing 10 as by riveting or spot welding and this housing supports the diaphragm 41 which with the outer wall of the housing forms a suction chamber 42. A spring 43 tends to hold the diaphragm in its inner position and by a suitable fitting 44 the suction chamber 42 is connected by a pipe 45 with the engine intake manifold as clearly shown in Figure 1.

Within the case l0 of the switch I provide an insulating medium shown in the form of a plate or sheet 46 of suitable electrical insulating and non-combustible material. This insulating plate or sheet is rectangular and of substantially the same width as the case 10 and which is guided for longitudinal movement by its engagement with the faces of the contact heads 16 and 16' and the lower edges of the side wall 29 of the insulating lining 29 in the case 10. A link 47 secured to the diaphragm 41 and extending into the case 10 through passageway 48 has a hooked end 49 engaging through an opening 50 in the adjacent end of the insulating plate so that as the diaphragm is deflected the plate will be shifted longitudinally. The link 47 is preferably resilient and may be of fiat spring metal.

When the engine is at rest and there is no vacuum or suction in the chamber 42 the spring 43 will hold the diaphragm in its inert or normal position during which condition the insulating plate will be shifted to the outer end of its movement to bring rectangular openings 51, 51' therethrough in alignment with the contact heads 16, 16' and the switch blade feet 24, 24' so that when the switch head is then depressed the switch blade yfeet may pass through the openings 51, 51 for electrical engagement against the terminal heads for closure of the starting motor circuit. However, as soon as the engine becomes self-operating, the suction effect within the suction chamber 42 will defiect the diaphragm outwardly and the insulating plate will be shifted outwardly to remove its passageways 5l, 51' from below the switch blade feet and to interpose solid portion between the switch blade feet and the terminal heads so that when the switch head 32 is then depressed the switch feet will encounter the insulating plate and will be prevented from making electrical contact with the terminal heads, so that the starting motor circuit cannot be closed. The force of the spring may be adjusted so that during the comparatively slow speed of rotation of the engine by the starting motor the vacuum will not be suicient to deflect the diaphragm against the resistance of the spring and so that the insulating plate will be held in its inner position where it will not interfere with the electrical functioning of the switch. However, when the engine has been started by the motor and is selfoperating, the force of the vacuum becomes sufficient to powerfully deflect the diaphragm for outward movement of the insulating plate for interposition thereof between the switch blade and switch terminals to prevent electrical contact.

With the arrangement shown in Figure 1, when the driver desires to start the engine he depresses the clutch pedal P which during its final or overthrow movement engages with and depresses the switch head 32 and the switch blade is moved downwardly with its Contact feet passing through the insulating plate openings for electrical engagement with the switch terminals and closure of the starting motor circuit. As soon as the driver hears that the engine has been started he releases the clutch pedal for return movement by its spring 53 and the increased suction resulting when the engine becomes self-operating causes outward deflection of the diaphragm and shifting of the insulating plate to insulating position so that while the engine remains self-operating the motor circuit cannot be closed by the switch even should the switch be depressed by the clutch pedal. Should the driver maintain lpressure against the switch by the clutch pedal after the engine has become selfoperating, the heavy suction on the diaphragm will tend to deflect it and the resulting pull on the insulating plate will tend to shift it outwardly to insulating position. The inner edges 52 of the insulating plate passageways may be beveled as shown in Figure 4 so that if the suction is strong enough the plate will be forcibly drawn outwardly to engage the beveled edges with the switch blade feet to cause raising of the contact feet away from the switch terminals so that the starting motor circuit will be thus automatically opened as soon as the engine becomes self-operating, even though pressure is maintained against the switch head. As soon as the engine stops or is below minimum speed, usually idling speed, the reduced vacuum will be unable to hold the diaphragm deflected and the insulating plate will be returned to its inner position with its passageways 51, 51 in position for electrical operation of the switch so that when the switch is depressed the starting motor circuit will be closed.

The insulating plate, when shifted to insulating position upon withdrawal of the switch blade 10 from the terminal head, will function to prevent arcing, and its movement between and against the contact heads and the switch blade end will keep the contact surfaces clean and bright so as to keep the switch resistance at a minimum.

I have shown a practical and eicient embodiment of the various features of my invention but I do not desire to be limited to the exact construction, arrangement and operation shown and described as changes and modifications may be made without departing from the scope of the invention as outlined in the accompanying claims.

I claim as follows:

1. An electrical switch comprising a housing, a plunger slidable in one wall of said housing, a switch blade secured to the inner end of said plunger and having contact ends, circuit terminals secured in the opposite wall of said housing below said switch blade contact ends, a plate of insulating material supported by and slidable on said terminals and having openings therethrough for passage of the contact ends into engagement with said terminals, and means for shifting said plate for interposition between said terminals and contact ends to prevent engagement of said ends with said terminals or to shift said plate for alignment of said openings for passage therethrough of said contact ends into engagement with said terminals.

2. An electrical switch comprising a rectangular housing, a plunger slidable through one wall of said housing, a switch blade secured to the inner end of said plunger and having contact ends, a lining of insulating material for the upper wall and side walls of said housing, circuit terminals supported in the opposite wall of said housing with their inner faces a distance below the side edges of said insulating lining to leave a guideway, a plate of insulating material shiftable in said guideway and having openings therethrough, and means for shifting said insulating plate where it will prevent engagement of said contact ends with said terminals when said plunger is depressed or to a position where the openings therein will permit engagement of said contact ends with said terminals.

3. In an electrical switch, an enclosing housing, a plunger extending through the top wall of said housing, a switch blade secured to the inner end of said plunger and having contact ends, circuit terminals supported in the bottom wall of said housing below said contact ends, a spring tending to hold said plunger and switch blade upwardly away from said terminals, a plate of insulating material supported by and slidable on said terminals and having openings therethrough normally in position between said contact ends and terminals whereby upon depression of said plunger said contact ends will pass through said openings for engagement with said terminals, a diaphragm chamber mounted on one end of said housing and a diaphragm therein, and a connection extending from said diaphragm through the end of said housing and connecting with said insulating plate whereby change of pressure in said diaphragm chamber will cause said plate to be shifted to withdraw its openings from said contact ends and to prevent engagement of said ends with said terminals.

HILYARD C. HOWSAM. 

